Estonians are renowned for their love for mushrooms. Foraging is one of the most loved hobbies in the small Baltic nation where almost 50 percent of the country is covered with forests. So it shouldn't be surprising that Estonian scientists are the ones to say that estimates of the amount of species of fungi in the world are wrong.
Up until now scientists have believed that the global richness of fungi should be somewhere between 1.5 and 5.1 million species. Estonian scientists have now proven that these numbers could be overly optimistic – the total number of fungal species is probably much lower. The scientists do not, however, make this claim out of thin air. For years Leho Tedersoo, Senior Research Fellow of the University of Tartu Natural History Museum, has lead a team of scientists in Estonia and partners in several different research institutes in the world. Together they gathered 15,000 soil examples from different countries with different climate. After sequencing the DNA of the samples, they found more than 45,000 fungal species. Although this number may not be final yet, Tedersoo is confident they can draw the conclusion that the biodiversity of fungi is not as numerous as believed in the past.
“Those previous estimations were based on mathematical models and assumptions of a constant plant-to-fungal species ratio across the world, but we show that these assumptions are badly incorrect,” says Tedersoo, a passionate mushroom enthusiast since the age of six. “Of course the estimations of how many different fungal species there are in the world vary from hundreds of thousands to tens of millions, and everybody who has formed an opinion on this number is convinced that the others get it wrong. To the best of our knowledge, this is the largest dataset of biodiversity studies published so far.“
The first task of the research was to estimate which regions have higher biodiversity of fungi than others and why. The first conclusion drawn from the research was that, much like plants and animals, fungi tend to have highest species richness patterns in tropical rainforests.
It may seem that to ordinary people the number of fungi in the world is of little importance. However, one should consider the fact that fungi are vitally important components of our ecosystem, assuring the plants have enough CO2 for photosynthesis.
“These global analyses of fungi enable us to better understand patterns and processes around us. So far, our understanding of global processes is very fragmented, especially what regards the soil biota,” Tedersoo says. “It also helps to understand how climate change affects soil biota or how to improve forest management to minimize the adverse effects on the environment.”
The DNA samples collected will provide answers to several other questions. For example, the scientists will start mapping functional properties of soil organisms in different ecosystems of the world to show how these organisms are adapted to climatic and soil-formation processes and to historical-biogeographical factors. Tedersoo assures that some of these findings will be introduced to the public in the next few years.
The article was first published in researchinestonia.eu.
Editor: M. Oll